Method of adapting a hand test socket for use in a workpress assembly

ABSTRACT

A method of adapting a hand test socket for use in a workpress assembly includes: providing a hand test socket having a base and a top cover. The top cover includes a clamp. The method includes the step: removing the top cover and the clamp and configuring the clamp for use in a workpress assembly. The step of configuring the clamp includes forming a frame and attaching the clamp to the frame.

This patent application is a divisional of U.S. patent application Ser.No. 08/764,965, filed Dec. 13, 1996, and now U.S. Pat. No. 5,869,976.

FIELD OF THE INVENTION

This invention relates to automated integrated circuit (IC) testing andmore particularly to IC handling systems.

BACKGROUND OF THE INVENTION

Integrated circuits (IC) virtually never wear out. Failure of an IC ismore often due to misuse or to a manufacturing defect. Misuses such asexcessive vibration, water damage, and extreme heat are difficult for amanufacturer to control. However, manufacturing defects seen byconsumers may be minimized by proper quality control. IC's often undergoextensive testing. Such testing seeks to identify defective IC's beforethe IC is used in a circuit board or other device. Testing should be asefficient and effective as possible.

High-speed IC testing systems have been developed which rely upon ahigh-speed robotic handler. The handler moves discrete IC packages intoand out of an IC test socket to enable electronic tests to be performedon the IC before the IC is attached to a circuit board or other device.Hi-speed robotic handlers, come in various configurations. Many includea workpress assembly which couples IC packages to the test socket base.

A typical prior art workpress assembly is illustrated by FIG. 1 whichshows a known IC handling workpress. The workpress includes a bladedelement which bolts directly to a portion of the workpress. The bladedelement is machined having four blades. The workpress includes a vacuumcup which extends through the bladed element between the blades. Theblades function to align IC packages with a test socket base.

IC packages include multiple conductive leads. The workpress bladespress the leads against the test socket base during testing. Ideally,the blades precisely and uniformly press the leads into the test socketto prevent lead damage. This ideal situation is sometimes unmet. What isdesired is a workpress which is precision made and which does not damageleads during high-speed IC testing.

After extended periods of high-speed IC testing, the blades may wear.When blade wear exceeds a certain acceptable limit, the workpressassembly may fail to properly align the leads with the test socket. Wornblades may deform or break the leads. Blades which are worn beyond theacceptable limit are normally replaced before the blades damage the IC'sto be tested. Blade replacement is expensive. What is desired is a wayof reducing the cost of blade replacement.

The blades are often custom fabricated, having a size and shape toaccommodate a particular IC package size. Custom fabricated blades arenormally custom machined to desired specifications. This machiningprocess is often performed by a specialized machine shop and isrelatively expensive. Using a specialized machine shop for bladefabrication may ultimately increase product costs for consumers. What isdesired is a way to eliminate the need for custom fabricated blades sothat consumers may save money.

The test sockets used in many IC handling systems are commerciallyavailable. Examples of test sockets are disclosed in U.S. Pat. Nos.5,009,608; 4,615,441; 4,758,176 and 5,387,120, the disclosures of whichare incorporated herein by reference. Normally each test socket includesa test socket base and a test socket cover. The test socket coverincludes a clamp which applies uniform pressure to the periphery of thepackaged IC when the cover is closed. The cover of these test sockets isclosed by hand.

One known method utilizes IC test socket bases for use with high-speedautomated IC testing. This involves removal of the test socket topcover. The top cover is then discarded and wasted. The base is attachedto the automated test system and is used for automated IC testing. Whatis desired is a way to recycle at least a portion of the top coverinstead of discarding the top cover.

SUMMARY OF THE INVENTION

There is a need to reduce the costs of manufacturing IC's. One costassociated with the manufacture of IC's is testing. This need and othersare met by the present invention. The present invention eliminates theneed for an expensive machining process and recycles a part of a testsocket which normally would be discarded--thereby, preserving resources.

The present invention includes a frame for holding a bladed element ofan IC handling system. The frame is specially formed and includes aface, a rim and a detent. The rim is formed on the face for aligning abladed element with respect to the frame. The detent is formed on therim. The rim and the detent cooperate to hold the bladed element.

In a preferred embodiment of the invention, the detent includes a hook.The hook includes a beveled edge for holding the bladed element. The rimextends along three sides of the face. The rim defines bolt holes sothat a bolt may extend through the bladed element and through the rim tohold the bladed element. The hook and the bolts cooperate to hold thebladed element.

In a further preferred embodiment, the frame is attachable as part of anIC handling workpress assembly. In particular, the frame is attachableto a workpress assembly. A test socket clamp attaches to the frame. Theclamp includes the bladed element. The bladed element has blades forcoupling an IC package to a test socket base.

The test socket clamp is formed from a portion of a test socket topcover. Forming the workpress assembly from a portion of a hand testsocket top cover assures proper alignment between the blades and thetest socket base.

In a further preferred embodiment, the test socket top cover includes atest socket clamp having hinge mounts. The hinge mounts fixedly attachthe test socket clamp to the frame. The hinge mounts have threaded holesand bolts. The bolts extend through the threaded holes to bolt the testsocket clamp to the frame. The frame includes a hook which holds thetest socket cover on the frame. The hook is configured for gripping aportion of a blade.

In a further preferred embodiment, the workpress assembly includes abladed element with four blades arranged in a rectangular format. Eachblade is formed having a beveled surface and a contact edge. The hookhas a beveled edge which conforms to the beveled surface of one blade.The beveled edge of the hook contacts the beveled surface of the oneblade to attach the test socket clamp to the frame.

The foregoing and other feature, aspects, and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention. When taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

For a further understanding of the advantages of the present invention,reference should be given to the following detailed description, takenin conjunction with the accompanying drawing, in which like parts havelike reference numerals and wherein:

FIG. 1 is an exploded perspective view of a prior art workpress assemblyhaving blades.

FIG. 2 is a perspective view of a known test socket.

FIG. 3 is an exploded perspective view of an embodiment of a workpressassembly in accordance with the present invention.

FIG. 4 is an exploded perspective view of a workpress assembly inaccordance with the present invention.

FIG. 5 is a perspective view of a system in accordance with the presentinvention.

FIG. 6 is a flowchart of a method in accordance with the presentinvention.

FIG. 7 is a flowchart of a method in accordance with the presentinvention.

DETAILED DESCRIPTION

FIG. 2 shows a test socket generally designated with the referencenumeral 70. The test socket 70 is in an open configuration. The testsocket 70 includes the base 58 and a top cover 72. The top cover 72includes the clamp 12. The top cover 72 and clamp 12 rotate to closeagainst the base 58 in the direction of the arrow 74.

The test socket 70 may serve a variety of functions. The test socket,for example, may serve as an IC storage and shipping container. A testsocket may be used to package IC's. The base of a test socket may beused for IC burn-in testing. Various types of test sockets 70 arecommercially available. Examples of test sockets are described in U.S.Pat. Nos. 5,009,608; 4,615,441; 4,758,176 and 5,387,120, the disclosuresof which are incorporated herein by reference.

The test socket clamp 12 defines a rectangular opening 76. The opening76 aligns with rectangular openings 84 and 86 in the top cover 72 and inthe base 58, respectively. The openings 76,84 and 86 enable an IC to beviewed within the test socket 70 when the cover 72 closes. Although thepresent invention is described in conjunction with a test socket clamphaving a top cover 72 with a clamp 12, any of a variety of test socketshaving a clamp, may be modified in accordance with the presentinvention.

FIG. 4 shows a workpress assembly generally designated with thereference numeral 10. The workpress assembly 10 includes a test socketclamp 12 and a frame 14. The frame 14 attaches the test socket clamp 12to the workpress assembly 10 to enable the workpress assembly to use thetest socket clamp for handling packaged IC's. One advantage of using atest socket clamp 12 with the frame 14 is to assure alignment betweenthe workpress assembly and any IC to be handled. Another advantage is torecycle test socket clamps 12.

The frame 14 includes a face 20, a rim 22 and a detent 24. Accordingly,the frame 14 is particularly configured for holding the test socketclamp 12. The rim 22 is formed on the face 20. The face 20 is square,having four sides. The rim 22 extends along each of three sides of theface 20. The rim 22 aligns the bladed element 16 of the clamp 12 withrespect to the frame 14. The detent 24 is formed on the rim 22 and isconfigured for holding the clamp 12 and the bladed element 16. Thedetent 24 includes a hook 30. The rim 22 defines bolt holes 32 andincludes blots 34. The hook 30 and the bolts 34 cooperate to hold thetest socket clamp 12 on the frame 14.

The test socket clamp 12 includes a bladed element 16 which has blades18 for coupling an IC package to a test socket base. The blades 18 arearranged in a rectangular format. Each blade 18 is formed with a beveledsurface 36 and a contact edge 38. The contact edge 38 is configured forpressing against IC leads without damaging the leads.

The hook 30 has a beveled edge 40 which conforms to the beveled surface36 of one blade 18. The beveled edge 40 of the hook 30 contacts thebeveled surface 36 of the one blade 18 to precisely hold the test socketclamp 12 in fine alignment on the frame 14.

The workpress assembly 10 includes a vacuum cup 44. The frame 14 definesa central opening 46. The clamp 12 defines a central opening 48 whichaligns with the opening 46 of the frame 14. The vacuum cup 44 extendsthrough the workpress assembly 10, the frame 14 and the clamp 12 to grippackaged IC's.

Forming the workpress assembly 10 from the clamp 12 of a hand testsocket top cover 40 assures fine and precise alignment between theblades 18 and an IC to be handled. Precise alignment minimizes theprobability of IC lead damage.

According to one aspect of the invention, the test socket clamp 12 isformed from a portion of a test socket top cover. Forming the clamp 12from a test socket top cover reduces waste by utilizing top covers whichare not normally recycled. The test socket clamp 12 includes hingemounts 50. The hinge mounts 50 are originally designed to rotatablyattach the clamp 12 with a test socket base. In accordance with thisaspect of the invention, the hinge mounts 50 are used to affix the testsocket clamp 12 to the frame 14.

The hinge mounts 50 have threaded holes 52. The bolts 34 extend throughthe threaded holes 52 to bolt the test socket clamp 12 to the rim 22 ofthe frame 14. Accordingly, the hook 30 and the hinge mounts 50 cooperateto affix the test socket clamp 12 to the frame 14.

FIG. 3 is an alternate embodiment of a test socket clamp 78 attacheddirectly to a portion of a workpress assembly 10. The clamp 78 has aninner periphery 80 which defines a central opening 82. The innerperiphery 80 is threaded for threadibly attaching the clamp 78 directlyto the workpress assembly 10.

FIG. 5 shows a high-speed IC handling system in accordance with thepresent invention and generally designated with the reference numeral54. The handling system 54 includes the workpress assembly 10, a tray56, and a test socket base 58.

The tray 56 holds packaged IC's 64. The workpress assembly 10 has an arm60 which moves the IC's 64 from the tray 56 to the test socket base 18.The arm 60 rotates between a first position (shown in phantom) where thearm 60 extends over the tray 56 to and a second position where the arm60 extends over the test socket base 18.

In the first position, the arm 60 lowers the workpress assembly 10 andenables the workpress assembly 10 to grip a packaged IC 64. The arm 60lifts the workpress assembly 10 and rotates to move the packaged IC 64.In the second position, the arm 60 lowers the workpress assembly 10 toplace the packaged IC 64 in the test socket base 18. This processrepeats.

The test socket base 58 tests the packaged IC's 64. Each packaged IC 64has a plurality of conductive leads 66. The workpress assembly 10 isspecially adapted to minimize any damage to the leads 66 duringinsertion of the packaged IC 64 into the test socket base 18. Inparticular, the workpress assembly 10 includes the bladed element 16.

When the arm 60 is in the second position, the bladed element 16 alignsthe leads with the test socket base 58. The bladed element 16 also andprecisely applies force onto the leads 66 of the packaged IC 64 tocouple the leads 66 to the test socket base 18.

According to one aspect of the invention, the bladed element 16 isformed from a portion of a test socket top cover. Forming the bladedelement 16 formed from a portion of a test socket top cover assuresproper alignment between the bladed element 16 and the test socket base18. Additionally, forming a bladed element 16 from a portion of a testsocket top cover minimizes manufacturing expenses which are associatedwith the manufacture of bladed elements. Further, the test socket topcovers are typically fabricated to close tolerances. Using a test socketcover as part of the workpress assembly 10 assures precise alignmentbetween the IC 64 and the test socket base 58; assures manufacturingintegrity and that close tolerances will be met; and assures that theleads 66 will not be damaged.

In Operation

FIG. 6 shows a flowchart of a method in accordance with the presentinvention generally designated with the reference numeral 108. Themethod 108 includes the step 110 of providing a hand test socket havinga base and a top cover having a clamp. Next, the step of 112 of removingthe top cover is performed. The step 114 of configuring the clamp foruse in a workpress assembly follows the step of removing.

According to one aspect of the invention, the test socket clamp has arectangular opening. The step 114 of configuring the clamp includes thestep of replacing the rectangular opening with a circular opening. Thecircular opening enables a portion of the workpress assembly extendthrough the clamp.

The clamp defines an inner periphery. The step 114 of configuring theclamp includes boring a central opening in the clamp and forming threadson the inner periphery. The inner periphery defines the central opening.An additional step in accordance with the present invention includesthreads the hand test socket to the workpress assembly.

FIG. 7 shows a flowchart of a variation of the step 114 of configuringthe clamp. This includes the step 116 of forming a frame, and the step118 of attaching the clamp to the frame. The step 120 of attaching theframe to a workpress assembly enables the workpress assembly to employthe clamp.

The step 116 of forming a frame includes forming a rim on the frame andboring bolt holes in the rim. The step of forming the rim of the frameincludes forming a detent including a hook on the rim. The hook has anedge. The method includes beveling the edge of the hook.

According to one aspect of the invention, the workpress assemblyincludes a portion having a vacuum cup. The vacuum cup extends throughthe clamp. The step of attaching includes extending the vacuum cupthrough the clamp and threadibly attaching the clamp to the portion ofthe workpress assembly having the vacuum cup.

While the foregoing detailed description has described severalembodiments in accordance with the present invention, understand thatthe above description is illustrative only and not limiting of thedisclosed invention. For example, the bladed element may attach in anyof a number of ways to a workpress assembly. Additionally, virtually anyclamp may be adapted from any number of test sockets having a cover. Itwill be appreciated that the embodiments discussed above and thevirtually infinite embodiments that are not mentioned could easily bewithin the scope and spirit of this invention. Thus, the invention is tobe limited only by the claims as set forth below.

We claim:
 1. A method of adapting a hand test socket for use in a workpress assembly, comprising the steps of:providing a hand test socketincluding:a base with two axially aligned pivot means separated by aspace; and a cover including a clamp having at least one blade, and alsohaving a pair of openings extending within said space between said pivotmeans, wherein each of said openings receives one of said pivot means,respectively, whereby said clamp pivots relative to said base about anaxis extending through said space and each of said pivot means; removingsaid clamp from said base; providing a frame having a rim defining arecessed portion, wherein the rim includes a pair of openings axiallyseparated by a space, and also includes a detent extending outwardlytherefrom; providing fastening means; inserting said clamp within saidrecessed portion such that said detent supportingly engages said atleast one blade, and such that said pair of openings of said clampbecome axially aligned with said pair of openings of said rim; and thenpassing said fastening means through each of the aligned openings,thereby attaching said clamp to said frame.
 2. The method of claim 1,including boring the pair of openings through the rim.
 3. The method ofclaim 1, wherein said detent includes a hook portion, and wherein saidinserting step causes the hook portion to supportingly engage said atleast one blade.
 4. The method of claim 3, wherein said hook portionincludes a beveled edge and said at least one blade includes a beveledsurface, and wherein said inserting step causes the beveled edge tosupportingly engage the beveled surface.
 5. A method of adapting a handtest socket to a work press assembly, comprising the steps of:providinga hand test socket including:a base with two axially aligned pivot meansseparated by a space; and a cover including a clamp having at least oneblade, and also having a pair of openings extending within said spacebetween said pivot means, wherein each of said openings receives one ofsaid pivot means, respectively, whereby said clamp pivots relative tosaid base about an axis extending through said space and each of saidpivot means; removing said clamp from said base; providing a framehaving a rim defining a recessed portion, wherein the rim includes apair of openings axially separated by a space, and also includes a hookportion extending outwardly therefrom; providing fastening means;inserting said clamp within said recessed portion such that said hookportion supportingly engages said at least one blade, and such that saidpair of openings of said clamp become axially aligned with said pair ofopenings of said rim; then passing said fastening means through each ofthe aligned openings, thereby attaching said clamp to said frame;providing a work press assembly having a surface; and attaching saidframe to said surface.